1. Field of the Invention
The present invention relates to a damping-force-adjustable-damper control device which adjustably controls the damping force of a damper that supports a wheel of a vehicle onto a vehicle body.
2. Description of the Related Art
Conventionally, damping-force adjustable dampers are used as a damper for a suspension device of a vehicle.
The damping-force adjustable dampers have a Magneto-Rheological Fluid (MRF) which generates damping force, change the viscosity in accordance with a magnetic field, and is filled in a cylinder. The damping-force adjustable dampers also have a coil arranged in a piston which slides inside the cylinder in the vicinity of a fluid path. As a current is allowed to flow through the coil, the damping-force adjustable damper causes a magnetic field to act on the MRFs flowing through the fluid path of the piston sliding inside the cylinder, and changes the viscosity of the MRFs in the fluid path, thereby obtaining desired damping force.
Regarding the damping-force adjustable dampers, JP 2008-238921 A discloses a configuration of a damper control device which generates a current to a damper in accordance with a target damping force and a detection result by a stroke sensor (see paragraphs 0021, 0022 and FIGS. 6, 7).
As is clear from FIGS. 6, 7 of JP 2008-238921 A, when the target damping force matches a sign of stroke of the damper, a current is set to be a positive value, and when the target damping force does not match the sign of stroke of the damper, the current is set to be zero.
In general, the foregoing setting is made through a periodical processing power by a Central Processing Unit (CPU). That is, a process is executed and a current is output for each period set in accordance with the processing power of the CPU.